Scrophulariaceae and Orobanchaceae 155 



combined and in places attains twice their extent in width; the 

 cell walls show irregularity. The epidermis, from herbarium 

 material, could not be described very accurately. 



The hairs of H. coccinea are of special interest because of 

 their large number, great size, and capitate-glandular character. 

 They are distributed over both stem and scales; as many as 20 

 were counted around the edge of a cross section of the stem of 

 reasonable thickness, which does not account for any that were 

 broken off. The "stalk" of each hair consists of from 3 to 5 

 cells; the basal cell is usually short, broad, and rounded, while 

 the others are elongated almost cylindrical; where two cells join, 

 there is a collar-like constriction, giving the "stalk" the appear- 

 ance of being jointed. The glandular tip is composed of 2 to 4 

 cells. Here again this genus is very similar to Orobanche which 

 will be described later. 



Proceeding from the last mentioned genus through the genera 

 of Orobanchaceae the vegetative axes become more or less in- 

 conspicuous though enlarged fleshy (in some genera) and tuber- 

 ous, and partly or wholly subterranean. 



In the transition genus Lathraea (Plate XIII, Fig. 14) the 

 vegetative axis has become a rhizome from 2 to 4 or 6 inches 

 long, and is provided with the hollow scale leaves concerning 

 which so much discussion has taken place, while from the an- 

 nual short-lived inflorescence numerous flowers arise. The 

 plant is described by Kerner (23, p. 135) as being destitute of 

 chlorophyll. "The subterranean stems are white, have a fleshy, 

 solid, and elastic appearance, and are covered throughout their 

 entire length with thick squamous leaves placed closely one 

 above the other. " The leaves are broadly cordate. The scales 

 being underground, naturally have lost their vegetative func- 

 tion, but are provided with cavities and structures for catching 

 animal prey. Solereder (24, p. 586) says that the function as- 

 cribed by Kerner and Wettstein to these structures is incorrect 

 according to Scherffel and Heinricher. Kerner describes two 

 kinds of structures formed on the internal surfaces of the scale 

 for which he suggests no special name in Lathraea squamaria; 

 others have called them glands. One kind is composed of a cy- 

 lindrical stalk cell and two cells forming a head, which project 

 into the cavity of the scale; the other variety, which does not 

 project into the scale, is composed of a tabular cell and two con- 



